Heat 2 teaspoons oil in a large saucepan over medium heat. Add onion, fennel, shallots, saffron, thyme, anise seed and garlic. Cook 7-10 minutes or until tender, stirring frequently. Stir in water, tomato paste and clam juice; bring to a boil. Reduce heat, and simmer 20-30 minutes.
Strain mixture through a sieve over a bowl; discard solids. Return mixture to pan; bring to a boil. Add potato; cook 5 minutes. Add fennel wedges; cook 4 minutes. Remove from heat, and keep warm.
Heat remaining 2 teaspoons oil in medium nonstick saute pan over medium-high heat. Season salmon with salt and pepper. Add fish to pan; cook 3 minutes on each side or until fish flakes easily when tested with a fork. If the pan is too small, cook the fish in batches.
In a serving bowl, serve 1 piece of fish with 1/2 cup of potatoes, 2 wedges fennel and 1/4 cup broth.